The effectiveness of the mRNA vaccines in preventing COVID-19 disease progression in 2021 set new expectations about the role of prevention interventions for the disease. Efficacy observed in the trials was more than 90%.1, 2 The efficacy of other vaccines evaluated in large randomised trials, such as the Oxford–AstraZeneca (70%) and Sputnik V (91%) vaccines, have been criticised for elements of the trial conduct and concerns about safety.3, 4 For that reason, mRNA vaccines have been most widely distributed in wealthier settings while other vaccines, such as Sinopharm and Sinovac, with some exceptions,3 have been provided in low-income and middle-income countries. The opportunity for head-to-head clinical trials evaluating vaccine comparative effectiveness no longer exists because so many people have received at least one dose of a vaccine. What happens in a clinical trial might also differ from the experiences of actual vaccine programmes and roll-outs. Until now, the real-world effectiveness of these lower profile vaccines has not been well established.